[Haemoglobin system of Black Sea round goby under experimental hypoxia conditions].

Haemoglobin of the Black Sea round goby (Neogobius melanostomus P.) resisting to external hypoxia was studied. Haemoglobin of this species was fractionated into 4 components (2 minor and 2 major ones) by the disk-electrophoresis in polyacrylamid gel. The major fractions were eluted and their respiration parameters were investigated. One of them showed high affinity for O2 (P50 5.81 +/- 0.74 mm Hg at pH 8.3) and heightened sensibility to pH (Bohr effect amounted to -0.81 +/- 0.09 at pH of 8.3 --> 7.5) simultaneously. Moreover, an acidosis incubation medium (pH 8.3 --> 7.5) decreased its O2 saturation by 12.8 +/- 1.4% (Root effect). The level of this fraction increased by 41.8% (p < 0.001) under the experimental hypoxia conditions (seawater O2 concentration range was 1.7-1.8 mg 1(-1); exposition--10 days). It affected blood respiration parameters and reflected the process of adaptation of this species to oxygen deficiency. The nucleotidtriphosphate level in red blood cells did not change. Swelling of circulated erythrocytes was observed simultaneously.